The incident involves the unwitting exposure of “tens of thousands” of Social Security numbers, according to a recent audit by the independent transparency and public-domain group Public.Resource.org. The identifying numbers were on the Internet for less than 24 hours after being discovered, but the damage was done. And unfortunately, the data-breach concerns some of the most sensitive types of transactions: Those made by nonprofit political groups known as 527s.

Every so often, 527s have to file tax forms to the IRS, which then get added to a database. The database itself is hardly a secret; the IRS has been sending updated records routinely to Public.Resource.org and other public-interest groups, and it’s a favorite among political reporters. But when the IRS told the group’s founder, Carl Malamud, to disregard the Form 990-Ts included in the agency’s January release, he took a closer look at the files in question.

Gary Price (gprice@mediasourceinc.com) is a librarian, writer, consultant, and frequent conference speaker based in the Washington D.C. metro area. Before launching INFOdocket, Price and Shirl Kennedy were the founders and senior editors at ResourceShelf and DocuTicker for 10 years. From 2006-2009 he was Director of Online Information Services at Ask.com, and is currently a contributing editor at Search Engine Land.